/****************************************************************************
 *
 * Copyright 2016 Samsung Electronics All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific
 * language governing permissions and limitations under the License.
 *
 ****************************************************************************/

/*
 *  X.509 base functions for creating certificates / CSRs
 *
 *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
 *  SPDX-License-Identifier: Apache-2.0
 *
 *  Licensed under the Apache License, Version 2.0 (the "License"); you may
 *  not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 *  This file is part of mbed TLS (https://tls.mbed.org)
 */

#include "tls/config.h"

#if defined(MBEDTLS_X509_CREATE_C)

#include "tls/x509.h"
#include "tls/asn1write.h"
#include "tls/oid.h"

#include <string.h>

typedef struct {
	const char *name;
	size_t name_len;
	const char *oid;
} x509_attr_descriptor_t;

#define ADD_STRLEN(s)     s, sizeof(s) - 1

static const x509_attr_descriptor_t x509_attrs[] = {
	{ADD_STRLEN("CN"), MBEDTLS_OID_AT_CN},
	{ADD_STRLEN("commonName"), MBEDTLS_OID_AT_CN},
	{ADD_STRLEN("C"), MBEDTLS_OID_AT_COUNTRY},
	{ADD_STRLEN("countryName"), MBEDTLS_OID_AT_COUNTRY},
	{ADD_STRLEN("O"), MBEDTLS_OID_AT_ORGANIZATION},
	{ADD_STRLEN("organizationName"), MBEDTLS_OID_AT_ORGANIZATION},
	{ADD_STRLEN("L"), MBEDTLS_OID_AT_LOCALITY},
	{ADD_STRLEN("locality"), MBEDTLS_OID_AT_LOCALITY},
	{ADD_STRLEN("R"), MBEDTLS_OID_PKCS9_EMAIL},
	{ADD_STRLEN("OU"), MBEDTLS_OID_AT_ORG_UNIT},
	{ADD_STRLEN("organizationalUnitName"), MBEDTLS_OID_AT_ORG_UNIT},
	{ADD_STRLEN("ST"), MBEDTLS_OID_AT_STATE},
	{ADD_STRLEN("stateOrProvinceName"), MBEDTLS_OID_AT_STATE},
	{ADD_STRLEN("emailAddress"), MBEDTLS_OID_PKCS9_EMAIL},
	{ADD_STRLEN("serialNumber"), MBEDTLS_OID_AT_SERIAL_NUMBER},
	{ADD_STRLEN("postalAddress"), MBEDTLS_OID_AT_POSTAL_ADDRESS},
	{ADD_STRLEN("postalCode"), MBEDTLS_OID_AT_POSTAL_CODE},
	{ADD_STRLEN("dnQualifier"), MBEDTLS_OID_AT_DN_QUALIFIER},
	{ADD_STRLEN("title"), MBEDTLS_OID_AT_TITLE},
	{ADD_STRLEN("surName"), MBEDTLS_OID_AT_SUR_NAME},
	{ADD_STRLEN("SN"), MBEDTLS_OID_AT_SUR_NAME},
	{ADD_STRLEN("givenName"), MBEDTLS_OID_AT_GIVEN_NAME},
	{ADD_STRLEN("GN"), MBEDTLS_OID_AT_GIVEN_NAME},
	{ADD_STRLEN("initials"), MBEDTLS_OID_AT_INITIALS},
	{ADD_STRLEN("pseudonym"), MBEDTLS_OID_AT_PSEUDONYM},
	{ADD_STRLEN("generationQualifier"), MBEDTLS_OID_AT_GENERATION_QUALIFIER},
	{ADD_STRLEN("domainComponent"), MBEDTLS_OID_DOMAIN_COMPONENT},
	{ADD_STRLEN("DC"), MBEDTLS_OID_DOMAIN_COMPONENT},
	{NULL, 0, NULL}
};

static const char *x509_at_oid_from_name(const char *name, size_t name_len)
{
	const x509_attr_descriptor_t *cur;

	for (cur = x509_attrs; cur->name != NULL; cur++)
		if (cur->name_len == name_len && strncmp(cur->name, name, name_len) == 0) {
			break;
		}

	return (cur->oid);
}

int mbedtls_x509_string_to_names(mbedtls_asn1_named_data **head, const char *name)
{
	int ret = 0;
	const char *s = name, *c = s;
	const char *end = s + strlen(s);
	const char *oid = NULL;
	int in_tag = 1;
	char data[MBEDTLS_X509_MAX_DN_NAME_SIZE];
	char *d = data;

	/* Clear existing chain if present */
	mbedtls_asn1_free_named_data_list(head);

	while (c <= end) {
		if (in_tag && *c == '=') {
			if ((oid = x509_at_oid_from_name(s, c - s)) == NULL) {
				ret = MBEDTLS_ERR_X509_UNKNOWN_OID;
				goto exit;
			}

			s = c + 1;
			in_tag = 0;
			d = data;
		}

		if (!in_tag && *c == '\\' && c != end) {
			c++;

			/* Check for valid escaped characters */
			if (c == end || *c != ',') {
				ret = MBEDTLS_ERR_X509_INVALID_NAME;
				goto exit;
			}
		} else if (!in_tag && (*c == ',' || c == end)) {
			if (mbedtls_asn1_store_named_data(head, oid, strlen(oid), (unsigned char *)data, d - data) == NULL) {
				return (MBEDTLS_ERR_X509_ALLOC_FAILED);
			}

			while (c < end && *(c + 1) == ' ') {
				c++;
			}

			s = c + 1;
			in_tag = 1;
		}

		if (!in_tag && s != c + 1) {
			*(d++) = *c;

			if (d - data == MBEDTLS_X509_MAX_DN_NAME_SIZE) {
				ret = MBEDTLS_ERR_X509_INVALID_NAME;
				goto exit;
			}
		}

		c++;
	}

exit:

	return (ret);
}

/* The first byte of the value in the mbedtls_asn1_named_data structure is reserved
 * to store the critical boolean for us
 */
int mbedtls_x509_set_extension(mbedtls_asn1_named_data **head, const char *oid, size_t oid_len, int critical, const unsigned char *val, size_t val_len)
{
	mbedtls_asn1_named_data *cur;

	if ((cur = mbedtls_asn1_store_named_data(head, oid, oid_len, NULL, val_len + 1)) == NULL) {
		return (MBEDTLS_ERR_X509_ALLOC_FAILED);
	}

	cur->val.p[0] = critical;
	memcpy(cur->val.p + 1, val, val_len);

	return (0);
}

/*
 *  RelativeDistinguishedName ::=
 *    SET OF AttributeTypeAndValue
 *
 *  AttributeTypeAndValue ::= SEQUENCE {
 *    type     AttributeType,
 *    value    AttributeValue }
 *
 *  AttributeType ::= OBJECT IDENTIFIER
 *
 *  AttributeValue ::= ANY DEFINED BY AttributeType
 */
static int x509_write_name(unsigned char **p, unsigned char *start, const char *oid, size_t oid_len, const unsigned char *name, size_t name_len)
{
	int ret;
	size_t len = 0;

	// Write PrintableString for all except MBEDTLS_OID_PKCS9_EMAIL
	//
	if (MBEDTLS_OID_SIZE(MBEDTLS_OID_PKCS9_EMAIL) == oid_len && memcmp(oid, MBEDTLS_OID_PKCS9_EMAIL, oid_len) == 0) {
		MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_ia5_string(p, start, (const char *)name, name_len));
	} else {
		MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_printable_string(p, start, (const char *)name, name_len));
	}

	// Write OID
	//
	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_oid(p, start, oid, oid_len));

	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len));
	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE));

	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len));
	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SET));

	return ((int)len);
}

int mbedtls_x509_write_names(unsigned char **p, unsigned char *start, mbedtls_asn1_named_data *first)
{
	int ret;
	size_t len = 0;
	mbedtls_asn1_named_data *cur = first;

	while (cur != NULL) {
		MBEDTLS_ASN1_CHK_ADD(len, x509_write_name(p, start, (char *)cur->oid.p, cur->oid.len, cur->val.p, cur->val.len));
		cur = cur->next;
	}

	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len));
	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE));

	return ((int)len);
}

int mbedtls_x509_write_sig(unsigned char **p, unsigned char *start, const char *oid, size_t oid_len, unsigned char *sig, size_t size)
{
	int ret;
	size_t len = 0;

	if (*p < start || (size_t)(*p - start) < size) {
		return (MBEDTLS_ERR_ASN1_BUF_TOO_SMALL);
	}

	len = size;
	(*p) -= len;
	memcpy(*p, sig, len);

	if (*p - start < 1) {
		return (MBEDTLS_ERR_ASN1_BUF_TOO_SMALL);
	}

	*--(*p) = 0;
	len += 1;

	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len));
	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_BIT_STRING));

	// Write OID
	//
	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_algorithm_identifier(p, start, oid, oid_len, 0));

	return ((int)len);
}

static int x509_write_extension(unsigned char **p, unsigned char *start, mbedtls_asn1_named_data *ext)
{
	int ret;
	size_t len = 0;

	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_raw_buffer(p, start, ext->val.p + 1, ext->val.len - 1));
	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, ext->val.len - 1));
	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_OCTET_STRING));

	if (ext->val.p[0] != 0) {
		MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_bool(p, start, 1));
	}

	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_raw_buffer(p, start, ext->oid.p, ext->oid.len));
	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, ext->oid.len));
	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_OID));

	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len));
	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE));

	return ((int)len);
}

/*
 * Extension  ::=  SEQUENCE  {
 *     extnID      OBJECT IDENTIFIER,
 *     critical    BOOLEAN DEFAULT FALSE,
 *     extnValue   OCTET STRING
 *                 -- contains the DER encoding of an ASN.1 value
 *                 -- corresponding to the extension type identified
 *                 -- by extnID
 *     }
 */
int mbedtls_x509_write_extensions(unsigned char **p, unsigned char *start, mbedtls_asn1_named_data *first)
{
	int ret;
	size_t len = 0;
	mbedtls_asn1_named_data *cur_ext = first;

	while (cur_ext != NULL) {
		MBEDTLS_ASN1_CHK_ADD(len, x509_write_extension(p, start, cur_ext));
		cur_ext = cur_ext->next;
	}

	return ((int)len);
}

#endif							/* MBEDTLS_X509_CREATE_C */
